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Re: paleonet Digital Images and Depth of Field



There are products on the market to do what you propose.  In fact I am
considering purchasing such a system from my local Leica rep.  A series of images
are taken at different planes.  Software then automatically deconvolutes the
images seamlessly into a single one with infinite depth of field.  The resultant
images are quite striking.  I work under a microscope but I suspect that the
system could be adapted to any stable photo stand.

Tim

TomDeVrie@aol.com wrote:

> Following the discussion of limitations in the depth of field of digital
> cameras, I wondered:
>
> Can the photographer with a digital camera overcome this problem by taking
> two pictures of the same object, but with slightly different distances to the
> object (say, a 1 cm difference), and then blend the two images in Photoshop
> to take advantage of the portions of each image that are best focused?
>
> I've started experimenting with this process and initial results are
> encouraging for a uniformly curved gastropod about 3 cm long.  Two pictures
> were taken with distances to obect varying by one cm.  Each image included a
> portion in focus and out of focus. One of the two images was re-scaled to a
> slightly larger size (e.g., 2048 to 2058 pixels) so that image dimensions
> matched.  An airbrush-eraser was used on two Photoshop layers, each layer
> having one of the images.
>
> The final images need to be 'flattened' to create a single image.
>
> Fortunately, there seemed to be no seam between the airbrushing done on the
> two components of the final image.  Airbrushing the same area produces a
> white patch, but the error can be caught when the airbrushing is first being
> done and remedied with an "undo" command.
>
> It may be that a small degree of poor resolution near the boundaries of the
> airbrushed areas is an acceptable price to pay for much better focus along
> the entire vertical distance of the fossil.
>
> Are there others on the listserve who have experimented more extensively with
> this approach?  Are there parameters beyond which the technique does not work?
>
> Tom DeVries

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Dr. R. Timothy Patterson
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